How to Get Ideas & Measure - Stewart Butterfield of Slack & Adam D'Angelo of Quora - Stanford CS183F

Key ideas

Butterfield says Slack came from years of fixing his team's own irritations and that ideas need filtering; Adam D'Angelo argues startups must measure retention.

From a machine transcript of the audio. Quotes link to the moment they are said.

1. 1

   Build from irritation, not speculation

   Butterfield suspects, while flagging this as after-the-fact analysis, that Slack succeeded because of a three-and-a-half-year design process nobody knew was one. His team fixed only what annoyed them most or was too obvious to pass up, spent minimal effort, and then lived with the result for months. He contrasts that with normal product debate, which he says is full of ego and speculation.

2. 2

   Ideas are easy, recognizing good ones isn't

   Butterfield says what looks like intuition is recognition built over time, citing Herbert Simon's work on chess grandmasters as described in Thinking, Fast and Slow, and his own 20 years of making software. He says this helps with small product decisions, but that he cannot judge about 95% of big app ideas he hears. He leans toward execution over ideas while saying you need both, since an idea has to survive contact with what can actually be built.

3. 3

   Glitch ended when the ideas ran out

   Butterfield describes being caught between the story that good entrepreneurs push on and a morning when he was sure the game Glitch would not work, while admitting he has little insight into how he reached that. He says the team had started with whiteboards of ideas to fix retention and worked through them until only the ones they had first rated worst were left. Even with money and engaged users remaining, he says it was hard to convince everyone else.

4. 4

   Most people don't tilt the umbrella

   Asked where he would look for ideas, Butterfield, unsure whether it works for others, points to his own frustrations as a consumer and says each is an opportunity. He tells of people on a narrow Vancouver sidewalk not moving their umbrellas out of others' faces, and concludes that most people either miss others' problems or cannot think of a fix. He sees a lot of opportunity for those willing to do it.

5. 5

   Measure retention by cohort

   In the second half, Adam D'Angelo tells founders to track users getting value today and then retention by cohort, since total usage can rise while every cohort declines. He compares that to a fire burning outward until the field runs out, and says the strongest position is usage per user rising over time. He also advises tracking weekly percent growth while not mistaking metrics for the underlying value to users.

In their words

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